Innovative test method for the reliable evaluation of joint sealants in concrete pavements

Joint sealants as indispensable filling systems in jointed plain concrete pavements (JPCP) are permanently exposed to various stresses during their service life, which often leads to a replacement of the sealing after approx. 7 to 10 years. Aside from seasonal unsteady climatic changes, the cyclical stresses caused by traffic and the ageing of joint sealants are especially significant. Considering the rising number of damages that occur within the overall "joint" system, an increased demand for a durable solution is requested as it is a relevant element for the life cycle costs of concrete pavements. In this context, a testing and ageing method was developed which comprises of the entire "joint" system, including the saw-cut concrete joint flanks, the primer as well as the joint sealant. This procedure depicts the decisive scenarios of in-situ stresses and allows the characterization of joint sealants. For this purpose, specimens were subjected to horizontal and vertical loads (static/cyclic) as well as to various ageing effects (temperature conditioning, UV-conditioning and freeze-thaw-cycles). After conditioning, a significant influence of the artificial ageing on the residual strength was observed in the tensile/shear tests. By comparing the artificially aged samples tested in the laboratory with extracted and in-situ aged samples, a reliable correlation was determined. Considering these system tests an initial approach was established which enables the evaluation of joint sealants in both unaged and artificially aged conditions on the basis of scientific parameters and limits.

Experimental and Numerical Studies of Stress Distribution in an Expanding Pin Joint System

Pin joints are widely used mechanisms in different industrial machineries such as aircrafts, cranes, ships, and offshore drilling equipment providing a joint with possibility of relative rotation about one single axis. The rigidity of the joint and its service lifetime depend on the clamping force in the contact region that is provided by the applied torque. However, due to the tolerance needed for insertion of a pin in the equipment support bore, the pin is prone to relative displacement inside the bore. The amplitude of this relative displacement usually increases as time passes and since the material of the support often has lower quality grade than the pin, it leads to creation of slack in the equipment and malfunctioning of the machine. An Expanding Pin System (EPS) can be a solution to this problem where the split sleeve expands to remove the gap while the joint is torqued. Therefore, slack in the joint system disappears and 360° contact area could be achieved, providing a better stress distribution and preventing the stress localization. Determining the EPS preload and the resulting contact pressure and stresses in the joint parts are important to avoid damaging to the contact surfaces of the joints and making the dismantling of the EPS difficult. Therefore, finding the amount of the required torque is a compromise between preventing slack in the EPS and prohibiting damage to the joint parts. Stress analysis in this study is performed based on the industrially recommended torque for the EPS type under study. This article reports the study conducted on the stress distribution and the magnitude of stresses exerted to the equipment support when EPS is installed on the machine. To achieve this purpose and to investigate the stress distribution in the joint, both experimental and finite element (FE) methods were used. The experimental results show how much of the applied energy to the EPS in the form of torque is spent to expand the split sleeve and test boss and also to overcome friction. The finite element analysis provides magnitude and distribution of stresses in the EPS components.

PENGARUH LOKASI BANGUNAN TERHADAP BENTUK DAN KONSTRUKSI RUMAH TRADISIONAL DI JAWA BARAT

Abstract:. West Java has so many topographical area, such as highland (mountain), low land (valley) and coastal area. All of these areas have differently influenced the typology of building system, which coming from their knowledge of local material, cultures, and technology, which have been delivered from their generation. The knowledge has been developed by times with trial and error process and become the local knowledge of this area (specific area). This paper will be elaborating the buildings (houses) on this 3 topographical area, with focusing on 3 systems of the building (house): lower, upper, and middle system. 3 parts of these building have been observed and created to propose the mapping of construction joint system. On this paper, the map of contraction system (which related to the area) has been explored on 3 traditional villages in West Java: Panjalin village at Majalengka District (located at coastal area), Cikondang village at Bandung District (located at highland area), and Mahmud Village at Bandung District (located at lowland area).Abstrak: Jawa Barat mempunyai geografis yang beragam, terdiri dari area pantai, dataran tinggi (pegunungan) dan dataran rendah. Kondisi geografis yang beragam ini, dihuni oleh masyarakat Jawa Barat yang memberikan ciri khas tersendiri dimana kehidupan tersebut berada, khususnya untuk masyarakat perkampungannya. Uniknya di Jawa Barat terdapat berbagai jenis bangunan tradisional yang mencirikan masyarakatnya, misalnya bangunan tradisional masyarakat di pantai, bangunan tradisional masyarakat di dataran rendah, dan bangunan tradisional masyarakat di dataran tinggi (pegunungan). Untuk itu, pada tulisan ini dilakukan pemetaan bangunan tradisional yang mewakili ketiga area tersebut, dengan melakukan pengamatan dan pengukuran bangunan. Pemetaan dilakukan pada 3 (tiga) lokasi yaitu kampung Panjalin–kabupaten Majalengka (yang mewakili area pantai), Kampung Cikondang–Kabupaten Bandung (yang mewakili area dataran tinggi (pegunungan), dan kampung Mahmud–Kabupaten Bandung (yang mewakili area dataran rendah). Setiap area mempunyai keunikan tersendiri, tetapi juga mempunyai persamaan, seperti konfigurasi bangunan, bentuk fisik bangunan, material, dll, tetapi ada juga perbedaan diadalam dimensi dan beberapa detail bangunan.

A Joint Optimization Model considering the Product User's Risk Preference for Supply System Disruption

Logistics distribution is the terminal link that connects the manufacturer and product user and determines the efficiency of the manufacturer’s service. Therefore, the disruption risk of the joint system is an essential factor affecting the product user experience. In this paper, while considering the product user’s supply disruption risk preference (PUSDRP), a biobjective integer nonlinear programming (INLP) model with subjective cost-utility is proposed to solve the manufacturer’s combined location routing inventory problem (CLRIP). According to the user’s time satisfaction requirement, a routing change selection framework (RCSF) is designed based on the bounded rational behavior of the user. Additionally, the Lagrange Relaxation and Modified Genetic Algorithm (LR-MGA) is proposed. The LR method relaxes the model, and the MGA finds a compromise solution. The experimental results show that the biobjective cost-utility model proposed in this paper is effective and efficient. The RCSF based on user behavior is superior to the traditional expected utility theory model. The compromise solution provides a better solution for the manufacturer order allocation delivery combinatorial optimization problem. The compromise solution not only reduces the manufacturer’s total operating cost but also improves the user's subjective utility. To improve the stability of cooperation between manufacturers and users, the behavior decision-making method urges manufacturers to consider product users’ supply disruption risk preferences (PUSDRPs) in attempting to optimize economic benefits for the long term. This paper uses behavior decision-making methods to expand the ideas of the CLRIP joint system.

Comparative Analysis of 3D Steel and Glulam Trusses Using ABAQUS

This study aims at developing an innovative and sustainable 3D truss system that can be applied in a variety of scenarios where intermediary propping is a hindrance. One prominent and pertinent application of such a system is in archaeological sites where long spans and no intermediary propping are desired. Previous research and studies have developed an innovative 3D steel truss for the same application. This study aims to further the innovation by providing a more sustainable alternative through Glulam and Glulam-Bamboo hybrid variations which are able to withstand similar loads as that of the steel truss but offering more sustainability and less impact on the environment as well as a light weight alternative. The results of such an alternative truss system are discussed here. One obvious problem faced with the alternative wood system was the large deflections observed and also certain regions with impermissible stresses. In addition, the proposed joint in the Glulam truss has been modelled and analyzed. It was found that the Glulam truss with lateral restraints at every quarter length of the span showed the best results in terms of deflection and stress developed. Also, the Glulam-Bamboo hybrid truss without any lateral restraints proved to be an equally effective alternative from a structural standpoint. The proposed joint system for the glulam truss also proved to be effective. The study concludes with a cost benefit analysis (CBA) between the steel, glulam and Glulam-Bamboo hybrid systems, which compares the viability of the proposed designs from an economic standpoint. The CBA shows that about 46% and 48% of costs are minimized on employing Glulam, Glulam- Bamboo respectively, instead of using Steel for the truss.

Hidden Dynamical Symmetry and Quantum Thermodynamics from the First Principles: Quantized Small Environment

Evolution of a self-consistent joint system (JS), i.e., a quantum system (QS) + thermal bath (TB), is considered within the framework of the Langevin–Schrödinger (L-Sch) type equation. As a tested QS, we considered two linearly coupled quantum oscillators that interact with TB. The influence of TB on QS is described by the white noise type autocorrelation function. Using the reference differential equation, the original L-Sch equation is reduced to an autonomous form on a random space–time continuum, which reflects the fact of the existence of a hidden symmetry of JS. It is proven that, as a result of JS relaxation, a two-dimensional quantized small environment is formed, which is an integral part of QS. The possibility of constructing quantum thermodynamics from the first principles of non-Hermitian quantum mechanics without using any additional axioms has been proven. A numerical algorithm has been developed for modeling various properties and parameters of the QS and its environment.